How to choose a camera for auto guiding in spectroscopy ?

[Robin Leadbeater]

Pour avoir tester une ASI183 refroidit et IMX178 refroidit et maintenant un IMX178 non refroidit, la différence se voit quand même bien, d'ailleurs les CMOS on besoin d'être bien plus refroidit en température que les CCD pour un faible bruit. Quand j'utilise mon IMX178 non refroidit en imagerie, avec 1s l'image est parsemée de bruit et bruit télégraphique.

I am glad someone else sees this. (I even bought a Lodestar to replace my ATIK 16ic-s because everyone said it was such a good guide camera but I sent it back because it was worse even in short exposures !)

[etienne bertrand]

Pour avoir des données chiffrées il faudrait que Christian Buil vienne nous donner son avis, peut être a-t-il fait des tests et mesures sur l'autoguidage ?

[Tom Love]

This is a very interesting discussion. I used to use a QHY5L-II, which I think is the same chip as the ASI120MM, on an Alpy600 on a 30cm Ritchey-Chretien with reducer working at F/6 (~1830mm focal length). But I recently changed to an ASI 174MM mini. While it's true that the ASI chip is large, and that the alpy reflecting slit mirror doesn't fill the whole of the field, I have found that astrometry.net mostly works on this setup, whereas the QHY was just too small a field for plate-solving.

So I wouldn't be put off by the chip being too large - mine works very well, and astrometry.net seems to be able to cope with the blank areas of the image.

[Olivier GARDE]

Hi Tom,

Thanks for your message about sensor size, yes Sony IMX 174 is a good choice to have a larger field.